Timing of fear expression in trace and delay conditioning measured by fear-potentiated startle in rats
Timing of fear expression in trace and delay conditioning measured by fear-potentiated startle in rats
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DOI：
10.1101/lm.66004
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发表时间：
2004-03-01
影响因子：
2
通讯作者：
Gewirtz, JC
中科院分区：
文献类型：
--
作者：
Burman, MA;Gewirtz, JC
在两个实验中，表达恐惧的时间过程中的痕迹（依赖于校园）与延迟（校园独立）条件反射的特点是高度的时间特异性，使用恐惧增强惊吓。在实验1中，各组大鼠被给予延迟恐惧条件反射或在条件刺激（CS）偏移和非条件刺激（US）开始之间具有3或12秒的跟踪间隔的跟踪恐惧条件反射。在测试过程中，延迟组表现出恐惧增强惊吓的CS的存在下，但不是在其偏移后，而微量组表现出恐惧增强惊吓CS期间和其偏移后。实验2比较了两个延迟条件反射组的时间过程中的跟踪条件反射后的恐惧表达的时间过程：一个匹配的跟踪条件反射组的CS持续时间，和其他方面的ISI。在所有组中，在计划的US发生之前都表现出恐惧，此后迅速恢复到基线水平。因此，在跟踪和延迟恐惧条件反射中，ISI是恐惧表达时间过程的关键决定因素。这些结果是翔实的神经结构，如海马体，在记忆过程中有关的时间信息的可能作用。
In two experiments, the time course of the expression of fear in trace (hippocampus-dependent) versus delay (hippocampus-independent) conditioning was characterized with a high degree of temporal specificity using fear-potentiated startle. In experiment 1, groups of rats were given delay fear conditioning or trace fear conditioning with a 3- or 12-sec trace interval between conditioned stimulus (CS) offset and unconditioned stimulus (US) onset. During test, the delay group showed fear-potentiated startle in the presence of the CS but not after its offset, whereas the trace groups showed fear-potentiated startle both during the CS and after its offset. Experiment 2 compared the time course of fear expression after trace conditioning with the time course in two delay conditioning groups: one matched to the trace conditioning group with respect to CS duration, and the other with respect to ISI. In all groups, fear was expressed until the scheduled occurrence of the US and returned to baseline rapidly thereafter. Thus, in both trace and delay fear conditioning, ISI is a critical determinant of the time course of fear expression. These results are informative as to the possible role of neural structures, such as the hippocampus, in memory processes related to temporal information.